An uncoupling mat is commonly used in building construction to bridge cracks in a concrete subfloor or to create a reinforced underlayment on a wood subfloor without the need of cementitious backer board. Installation of an uncoupling mat allows a contractor to safely build up a highly flexible subfloor or a highly crack prone floor with the same product.
An uncoupling material is typically composed of a bottom fabric or fleece layer and an upper layer of plastic configured to receive a mortar bed and to key in the mortar. In the application of the uncoupling mat, the fabric or fleece bottom layer of the mat is adhered to the subfloor. Tiles may be installed by bonding to the top plastic surface of the mat with mortar. Should a large shift or movement in the subfloor occur, the plastic layer “uncouples” from the fabric while maintaining the mortar bed intact.
The typical application involves using a first layer of mortar adhesive, or thin set, to bond the bottom of the fabric layer to the subfloor. This time consuming installation is typically accomplished with a latex modified cementitious mortar.